Nghiên cứu ảnh hưởng của các yếu tố công nghệ đến chất lượng bề mặt gia công trên máy cắt dây tia lửa điện OCT 150MA khi gia công đầu dò máy đo CMM

NGHIEN ClJfU ANH HlTONG CUA CAC YEU TO CONG NGHE DEN CHAT LirONG BE MAT GIA CONG TREN MAY CAT DAY TIA LUA DIEN 0CT-150MA KHI GIA CONG DAU DO MAY DO CMM STUDYING THE EFFECT OF TECHNICAL FACTORS TO THE MANUFACTURED SURFACE QUALITY ON THE WIRE - CUT EDM MACHINE (OCT-150MA) WHEN MACHINING THE CMM PROBE Dirong Hai Nam Khoa Ca Trudng Dai hoc Kinh te - Ky thuat Cong nghiep Den Toa soan 04/05/2014, chap nhan dang 04/06/2014 Tom tat: Nghien cCfu SL/ anh hLfdng ciia c^c thdng sd cong nghe din chat luong gia cdng tren may cit day tia li>a dien la muc tieu quan ddi vdi nganh san xuSt co hien Bai bao trinh bay kit qua danh gia muc dd anh hu'dng cua cac yiu td cdng ngh#: vSt lieu didn eye, vat iieu gia cdng dien ap, ddng xung dien c^t, tdc cat va thdi gian cSt din chat luong b i mat gia cdng d^u may CMM tren may c§t day tia lua ^en OCT-150MA Day la ca so cho vi^c nghien cCfu cac khia cgnh khac cua qua trinh gia cdng bing tia lua di^n, gop phin thiic diy su phat triln cua cac ITnh vyc gia cdng hien dai TLP khda: May cit day EDM, gia cdng micro, dau dd micro Abstract: Studying the effect of technical factors to the manufactunng quality on the wire-cut EDM machine is an important target for the cun-ent mechanical fields The paper presents assessment results of the impact of technical factors such as electrode materials, processing matenals, power-lines cut, cutting speed and cutting time to the surface quality when machining the CMM probe using the wire-cut EDM OCT 150MA They are the basics for researching other aspects of the EDM processing and for contributing to the development of various modern machining processes Keywords: Wire-cut EDM, micro machining, micro probe L G i a i THIEU Vdl dac diem ciia nganh co tii cuoi thap men 80 ciia th§ ky XX den nay, r4t nhieu doanh nghiep nudc da ti-ang bi cac loai may, thiet bi su dung cong nghe EDM nham cai tien phuong phap gia cong, nang cao gia tn cua san pham [1] Ben canh nhirng kk qua dat duoc vd mat cong nghe thi noi chung gap nhiing kho khan nhat dinh ve ky thuat va hieu qua kinh te sii dung cac may va thi6t bi bdi vi cac nguyen nhan sau Viec khai thac cong nghe cSt day chua hieu qua ^ * ^^^^ ^ " ^ ^^ "^^^ Sia cong chua cao TAP CHI KHOA HOC & CONG NGHE S6 - 2014 KHOA HOC a CONG NGHE chua kiem soat duoc cac y6u td cdng nghe • VSn dd dat la lam the nao d6 nang cao hieu qua khai thac, sir dung loai may nay? Bai bao trinh bay ket qua nghien ciru anh hudng cua cac yiu td cdng nghe din chk luong be mat gia cong tren may cat day tia Ilia dien (Wire Cut Electro Discharge Machinmg OCT-150MA) Cac ket qua nghien cim duoc thuc hien tai tam thi nghiem Co cliinh xac (Micro-Machming Lab) ciia Trudng Dai hoc Cdng nghe qudc gia Dai B5c (National Taipei University of Technology NTUT) • Dien cue (ddng vai trd la dung cu cat)' cd cimg thap hon nhieu so vdi vat heu phdi Vat heu phdi thudng la nhiing vat heu cimg va da qua nhiet luyen nhu thep da tdi, cac loai hop kim ciing Vat heu dien cue tiiudng la ddng, grafit Thuc chat ciia phuong phap gia cdng tia liia dien la sa tach vat heu khdi b i mat phdi nhd tia liia dien So nguyen ly cua phuong phap gia cdng bang tia liia dien duoc md ta nhu hinh 2.2 Ly va muc tieu dat dietyc thirc hien thi nghiem PHU*aNG PHAP THi NGHIEM • 2.1 Dac di4m cua phiFcng phap gia cong tia lu>a dien - Ngluen ciiu su anh hudng cfia cac yeu to cdng nghe den chat luong be mat gia cdng tren may cit day tia liia dien; Ly do: Gia cdng tia lua dien la phuong phap gia cdng bang each phdng dien 5n mdn tren co sd tac dung nhiet ciia xung dien duoc tao su phong dien giiia dien cuc[2] - Giup cho viec lua chon che dd cdng nghe duoc hop ly nham dam bao viec nang cao chat luong va gia san phSm, • Vat lieu dung cu cat va vat Heu phdi ddu phai CO tinh chat dan dien tdt; - Lam CO sd cho viec nghien ciru cac khia canh khac cua qua trinh gia cong bang tia lua dien • Moi truong gia cdng klii gia cdng phai su dung mot chat ldng dien mdi lam moi trudng gia cdng • Muc tieu dat duoc - Che cdng nghe hop ly thda man cac yeu cau ky thuat, - San phSm la dau dd may CMM _^ - c • _.—^ -.-_- _ ^Pf}dH+) Hinh So- dd nguyen ly gia cong tia lira dien Day la dung dich khdng dan dien d dieu kien lam viec binh Ihuong • Phuong phap gia cdng tia liia dien cd the tao duoc cac mat dinh hinh la duong thing, dudng cong, cac ranh dinh hinh, cac be mat cd profin phiic tgp vdi bdng be mat tuong ddi cao 2.3 Vat lieu thi nghiem Trong ndi dung cua bai bao, tac gia da su dung thep khdng gi AISI 304 lam vat heu d i nghien cmi vdi cac dac diem sau Thep khong gi AISI 304 (tuong duong vdi mac 8CrI8NilO ciia Viet Nam) la loai diin hinh nhat nhom thep khdng gi Austenit Day la loai thep duoc ung dung rat rdng rai thuc te vi nhiing uu diem sau • Tinh chdng an mdn cao, dn dmh cac moi trudng nhu nudc, dung dich mudi, mot sd axit (HNO3.), cd kha nang chiu nhiet cao (900-1000''C) vi vay chiing duoc dimg nhieu cdng nghiep TAP CHl KHOA HOC & CONG NGHE S6 - 2014 KHOA H p c a CONG NG hoa diu, thuc pham, >• te, • Tinh deo cao (= 45-60%) dl gia cong can, dap, go d hang thai nguoi nen dugc dimg nhieu cac thiet bi hoa hoc va dimg gia dinh; Hai kieu mach TR va RC duoc sii dung lan luot tren may OCT 150MA de gia cong diu may CMM • Co tinh dam bao, co kha nang chong mai mdn tdt nen thudng duoc dung lam dung cu ki6m, khuon dap Ben canh no co mot so nhiing nhuoc diem: - Dit tiin, chira nhieu Ni, - Kho gia cong cat got deo quanh, phoi kho gay, be mat gia cong de bi bien ciing, dao nong hon va co xu hudng tao leo dao nhieu hon Noi chung, day la loai kho gia cdng so cac loai thep khong gi; - Bi an mon hong mot so trudng hop cu the nhu an mon theo bien gidi hat d vimg anh hudng nhiet cua moi han hoac chi tiet phai thudng xuyen lam viec d nhiet 400800°C, an mdn tap trung Hinh May cat day EDM OCT~150MA Thong so ky thuat chinli the hien tai bang Bang Thong so ky"thua;t chinh ciia may EDM OCT-1 SOMA 2.4 Cac gia thi4t cua thi nghiem Cac thi nghiem duoc thiet ke vdi nhiing gia thiet sau: • Chat luong chat dung moi va dieu kien dong chay chat dien moi tat ca cac thi nghiem la nhu nhau, • Tiet dien day coi nhu khong doi suot qua trinh thuc hien thi nghiem, TRType Working fluid • Nhiet moi trucmg gia cong luon on dinh va bang nhiet phong thi nghiem; • Tong hop cac nhieu anh hudng den chat luong be mat gia cong la on dinh va khong doi suot qua trinh thuc hien thi nghiem 2.5 Bd tri va l^p dat thu'c nghiem Thiet bl sii dung cho thi nghiem la may cat day tia lua dien (Wire Cut Elecho Discharge Machinmg OCT-150MA)nhir hmh2 10 Capacitance RC Type Japan EMD Series (MIBARMETALWORKINGOIL) lOOOOOpF rough machining lOOOpF machining So lap dat may cit day liia dien EDM OCT-150MA duoc the hien h-en hinh Chi tiet gia cong lap tren true chinh dien cue day gan vol dau may Vi tri cua dien cue day so vdl chi tiit gia cong duoc dieu khien bdi he thong servo ya nguon cung cap Khi dien cue day tien gan bi mat chi tiit, nhung tia TAP CHI KHOA HOC & CONG NGHE S6 - 2014 KHOA HOC & CONG NGHE lua dien duoi dang xung, phdng va tit vdi tan sd cao se lam ndng chay hoac bdc hoi mot vung nhd cua bi mat chi tiit Kim loai ndng chay duoc lam ngudi sau dd hda rSii nhting hat hinh ciu va duoc lam phang dl bdi ap luc ciia nudc ion hda Nudc ion hda dugc bom vao theo khe hd giua dien cue day va chi tiit gia cong di day di nhiing hat bi xdi mdn day OCT-I50MA qua cac mach RC va Tr (nhu minh hpa tren hinh 4, va dd thi d hinh 6) tac gia nhan thay rang vdi cimg mdt dien tich la 115,7x153,4 |im thi nham be mat gia cdng cat voi mach Tr co mm cao hon Vi anh chat lugng be mat gia cong bang mach RC va mach Tr nhu tren hinh Vdi mach RC, tren be mat chi tiet nhiiu hd map md duoc tao va ro rang hon qua trmh phdng dien lam bdc hoi vat heu so voi su dung mach Tr Diiu co nghia, chit lugng nham bi mat gia cdng sii dung mach Tr tdt hon sii dung mach RC Hinh So- dd rap dat may EDM OCT-150MA K^T QUA VA THAO LUAN Vdi ket qua thi nghiem la san phim diu tii mach gia cdng khac la Tr va RC tren may cit day tia liia dien OCT-150MA cho thay su anh hudng cua cac thdng sd cdng nghe nhu vat lieu cat, ddng xung dien cat, tdc cat, den chat lugng be mat gia cdng cat bang tia lua dien tren may cat day, Vdi vat lieu thi nghiem la thep khdng gl AISI 304, tac gia tiin hanh so sanh ket qua vdi cac tieu chi: kich thudc, nham be mat dat dugc tir san pham dau dd CMM Ket qua chi ring* dien ap xung cd tac ddng den lugng bdc tach vat lieu, la hang s6 vat ly phu thupc vao cap vat heu dien cue - phdi, Dong xung anh hudng ldn nhat din lugng hdt vat heu phdi, mdn dien cue va chat lugng bi mat gia cdng Trong moi quan he vdi lugng bdc tach vat lieu, ddng xung cang ldn thi luong hdt vat lieu cang Ion, nham gia cdng cang tang va mdn dien cue cang giam Di sau so sanli nham be mat gia cong clii tiet dau dd may CMM tien may cat Hinh So- mo phong nham bk mat chi ti^t vo-i mach RC tren may EDM OCT-150MA Hinh So> dd mo phong nham b i mat chi ti^t vdi mach Tr tren may EDM OCT-150MA Hinh D6 thj nham b i mat chi t i i t vdi mach Tr tren may EDM OCT-150MA TAP C H I KHOA HOC & CONG NGHE SO - 2014 KHOA HOC & CONG NGHE gian cat, , den chat lugng b i mat dau gia cong dau may CMM tien may cat dayOCT-150MA, • Qua trinh nghien cuu thuc hien thong qua he thong ly thuyet ket hop vdi thuc nghiem de tir dua co sd cho viec toi uu hoa qua trinh cat tren may cat day tia liia cten Kit qua dong thdi ciing lam co sd cho viec nghien cim cac khia canh khac cua qua trinh gia cong bang tia liia dien, gop phan hoan thien viec xac dmh va dieu chinh cac thong so cong nghe gia cong tren may cat day noi chung va gia cong tien may micro WEDM noi neng RC pulse generator Tr pulse generator Hinh Vi anh chat limng nham b i mat gia cong bang mach RC va Tr Huong nghien cuu tiep: • Nghien ciiu su anh hudng cua cac yeu to nhieu den qua trinh gia cong (vi du ap suat, nhiet do, ) ; K^T L U A N • Ket qua nghien ciiu dS chi su anh hudng cua cac thong so cong nghe nhu dien ap xung, dong xung dien cat, toe cat, thdi • Nghien cim su anh huong cua cac thong so cong nghe den qua tiinh gia cong thuc hien tien cac loai vat heu khac T A I LIEU THAM KHAO [I] PGS TS Truong Ngoc Thuc, "Cac phuong phap gia cdng mdi", Nxb Giao due, 1995 [2] TS Vu Hoai An, "Gia cdng tia liia dien CNC", Nxb Giao due, 2003 [3] Masuzawa T, Fujino M, Kobayashi K and Suzuki T 1985 Wire electro-discharge grinding for micro machining Ann CIRP 34 431-4 [4] Sheu D Y and Masuzawa T 2003 Automatic produchon of micro holes by EDM Int T Elech Mach, 15-9 [5] Takezawa H, Hamamatsu H, Mohri N and Saito N 2004 Development of micro-EDM-center with rapidly sharpened electrodes J Mater Process Technol 149 112-6 Thdng tin hen he: Dmmg Hai Nam Dien thoai 0985941969 - Email- dhainam.uneti@moet.edu Don VI cdng tac: Khoa Co - Trudng Dai hoc Kinh ti Ky thuat Cdng nghiep TAP CHI KHOA HOC & CONG NGHE SO - 2014 ... phap gia cong tia lu>a dien - Ngluen ciiu su anh hudng cfia cac yeu to cdng nghe den chat luong be mat gia cdng tren may cit day tia liia dien; Ly do: Gia cdng tia lua dien la phuong phap gia. .. mach Tr tren may EDM OCT- 150MA TAP C H I KHOA HOC & CONG NGHE SO - 2014 KHOA HOC & CONG NGHE gian cat, , den chat lugng b i mat dau gia cong dau may CMM tien may cat dayOCT -150MA, • Qua trinh... dl gia cong can, dap, go d hang thai nguoi nen dugc dimg nhieu cac thiet bi hoa hoc va dimg gia dinh; Hai kieu mach TR va RC duoc sii dung lan luot tren may OCT 150MA de gia cong diu may CMM